class Solution {
public:
    int minDistance(string word1, string word2) {
        
        int n=word1.size(),m=word2.size();
        vector<vector<int>> dp(n+1,vector<int>(m+1,0x3f3f3f));
        dp[0][0]=0;
        for(int i=1;i<=n;++i){
            dp[i][0]=i;
        }
        for(int i=1;i<=m;++i){
            dp[0][i]=i;
        }
        for(int i=1;i<=n;++i){
            for(int j=1;j<=m;++j){
                if(word1[i-1]==word2[j-1]){
                    dp[i][j]=min(dp[i-1][j-1],dp[i][j]);
                }
                else{
                    dp[i][j]=min(dp[i-1][j],min(dp[i-1][j-1],dp[i][j-1]))+1;
                }
            }
        }

        return dp[n][m];
    }
};
